Heating and Ventilating

Monodraught managing director Professor Terry Payne suggests that natural ventilation offers a real opportunity to help homeowners, businesses and government reduce energy costs and their carbon footprint
Climate change is one of the biggest threats to our environment so it is important to focus on sustainable, energy-saving equipment that can help the UK achieve its 20% Kyoto target for reducing carbon emissions. And with energy bills also rising at an unprecedented rate, it is an opportune time to consider natural ventilation as an alternative to energy-hungry air conditioning.

Roof-top-configured, turret-based natural-ventilation technology was often considered to be something of a black art. But nowadays this innovative technology with its sophisticated controls is widely recognised as one of the most reliable and effective means of harnessing the wind's potential as a sustainable energy source.

Recent developments in digital microprocessor-based control technology also means that it
is reliable and predictable. In fact, various seasonal ventilation strategies can now be created to react to everything from wind and rain to CO2 and temperature levels, while retaining a manual override facility.

The UK is well ahead of the rest of the world in this technology, and the CIBSE group on natural ventilation is engaged in a campaign of promoting it. Also, organisations such as the Carbon Trust support the principles and benefits of natural ventilation.

Private housing
In the private-house sector, however, there are concerns regarding in particular the new generation of eco-homes which, with their high insulation standards, are extremely airtight. In practice, this means homes likely to overheat and suffer poor air quality.

To counter the problem, architects and house builders should be encouraged to adopt natural ventilation systems equipped with solar-boosted fans. These can be supplied in a variety of complementary designs including some systems concealed within an architecturally attractive chimney-effect design.

There is a need to remove grey areas surrounding the use of natural ventilation in non-domestic buildings, following the initiative taken by the Carbon Trust. There should be a code that informs architects, m&e contractors and builders how to specify natural ventilation - not only for new build, but also for the thousands of commercial and public buildings that currently suffer from overheating or excessive solar heat gain.

Schools and colleges are by far the biggest market for natural ventilation products, and this market is still growing at around 30% a year. The fact that architects and designers clearly recognise the importance of well-ventilated, healthy environments for learning is supported by empirical evidence that the provision of fresh air through natural ventilation (and for that matter the provision of daylight using natural lighting) does promote learning and improves academic results.

We are all being encouraged to reduce our carbon footprint and meet the Energy Performance of Buildings Directive. To resolve the ambiguities of Part L of the Building Regulations, representations, prepared by Dr Martin Liddament, are being put forward to the government.

Building design
There is currently a debate with regard to the design of buildings to comply with Building Regulations Part L2A and the SBEM Regulations, where the calculations appear to favour air conditioning over naturally ventilated buildings.

For all of our sakes, this matter must be resolved because the benefits of wind-driven and solar-driven natural ventilation systems are too important to ignore. They apply atmospheric principles and the natural effects of the wind to bring fresh air into a building and extract stale warm air from it, using natural buoyancy.

Fortunately, attitudes to natural ventilation are well established and proven - as demonstrated by a recent refurbishment project at Pool Audi in Dorset. When managing director David Kelly authorised the remodelling of the 1,600m2 building, improving ventilation was one of the priorities. This was especially necessary because the fully glazed frontage of the south-west facing showroom caused high internal temperatures.

While this made the environment uncomfortable for staff and visitors Kelly wanted to avoid typical solutions involving unsightly ceiling-mounted cassette units, which are expensive to install, often noisy, and consume large amounts of energy.

His building services consultancy, Worldwise, suggested natural ventilation systems as the environmentally friendly alternative and estimated that Monodraught's Windcatcher systems would pay for themselves within two years thanks to the savings on running costs, maintenance and other factors.

The Windcatchers created a comfortable atmosphere for staff and customers without resorting to an energy-hungry mechanical system. And, instead of unsightly air-conditioning units, the ceiling features attractive grilles.

Kelly says: 'Typically, in premium buildings, air conditioning is specified to create an ideal temperature despite the prohibitive energy and environmental costs. Windcatchers don't use any power, yet still achieve a perfectly comfortable showroom temperature. Natural ventilation does everything we expected, and it is incredibly efficient and incredibly cheap to run. I believe this is the way all businesses will have to go in the future.'

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